#pragma once
using namespace std;
#include<iostream>//standard iostream operations
#include<limits>//numeric limits
#include<cmath>//mathematical functions
#include<cstdlib>//C-string functions
#include<cstddef>//C-library language support
#include<fstream>//file input and output
#include<cctype>//character classification
#include<ctime>//date and time functions

enum Error_code { success, fail, range_error, underflow, overflow, fatal, 
	not_present, duplicate_error, entry_inserted, entry_found, internal_error };
